GC/MS Analysis, Anticancer, Antimicrobial Potentials and In Silico Evaluations of Extract Fractions of Soft Coral Sarcophyton gracile

Sarcophyton gracile, Red Sea soft coral, is a rich source of bioactive secondary metabolites. In this article, we targeted the extraction and isolation of three main chromatographed fractions (A, B, and C). We investigated their efficacy as anticancer agents against hepatocellular carcinoma (HepG2) and colon carcinoma (HCT 116) cell lines, as well as their antimicrobial activities against pathogenic bacteria (Staphylococcus aureus, Bacillus subtilis, Salmonella typhi and Klebsiella pneumoniae), and the pathogenic fungal species, Candida albicans and Penicillium glabrum. Fraction B showed strong cytotoxicity against HepG2 with IC50 53.7 µg/ml compared with Sorafenib drug 75.64 µg/ml and moderate activity against HCT 116 with IC50 48.19 µg/ml compared to Sorafenib 35.74 µg/ml. fractions A and C showed moderate to weak activity against the mentioned cell lines. All examined fractions (A, B and C) have strong antibacterial activities against B. subtilis, S. aureu, K. pneumonia and S. typhi, recording zone of inhibition (ZOI) value about (22- 35 mm) in diameter, and strong antifungal activity toward C. albicans and P. glabrum with ZOI value about (27-32 mm) and (10-25 mm), respectively compared to control. GC-MS investigation of the three main examined fractions characterized 63 components, demonstrating that fraction A is rich in sesquiterpene, fatty acid derivatives, steroids, and fraction B is rich in fatty acid derivatives, diterpenes, and steroids, while fraction C is rich in fatty acid derivatives and steroids. Molecular docking simulation studies were conducted to predict the possible binding affinity mechanism of the most abundant bioactive components to two potential enzymes. The in-silico results revealed that many of the examined compounds had a reasonable binding affinity, which supports their potential as dual anticancer candidates.